266 
CAPTAIN W. DB W. ABNEY AND DR. A. SCHUSTER 
spectrum, which had before and after the eclipse been photographed on the same 
plate as a reference. Towards the less refrangible side, the solar line E forms the 
approximate boundary, though on the southern side the continuous spectrum reaches 
a little further. The continuous spectrum extends from the moon’s limb on both 
sides with great intensity up to a certain height, then there is a sudden falling off 
in intensity, decreasing steadily on the southern side from this point up to a height 
at which it cannot be traced any more ; but on the southern side there seems to 
be a slight increase again in intensity as we go towards greater distances from the 
sun’s limb ; then there is again a sharp boundary at which a sudden decrease in 
intensity is noticed. From that point the continuous spectrum gradually vanishes. 
The following numbers will give an idea of the extent to which the continuous 
spectrum reaches at different points on the southern side : 
Height of continuous spectrum 
solar radius. 
in terms of a 
N ear F. 
•2 
For X —4480. 
•37 
■53 
1-23 
Near G. 
•29 
•60 
1-47 
The first column refers to the first sharp decrease in brightness; the second column to 
the second falling off in intensity ; and the last column gives the limit to which the 
continuous spectrum can be traced. On the northern side the spectrum does not reach 
as high, thus near G it cannot be traced further than ‘9 of a solar radius. 
In the lower regions the spectrum appears perfectly continuous, but in the upper 
regions the solar line G appears reversed. 
Fig. 2. 
goo 50 800 50 700 50 600 50 50Q 50 400 
I I- I I I I l i i i 1 i l I ! I. _| I .1 I 1 l i 1 l 1 i i l ■ 1 1 i i i I 1 i i I I I I i I I L i_LJ_1_J 
34. 35 36 37 33 39 40 41 42 43 44 45 46 47 42 49 
Spectrum of the corona, from a photograph. The top scale is that of the micrometer, the bottom 
